Ballpoint pen



FIG. 1 is a front view of a ballpoint pen of the present invention;

FIG. 2 is a left side view thereof;

FIG. 3 is a back side view thereof;

FIG. 4 is a right side view thereof;

FIG. 5 is a top plan view thereof; and,

FIG. 6 is a bottom view thereof.

The stippling shown on the grip of the pen barrel in FIGS. 1, 2, 3, 4, and 6 represents a contrast in material and is part of the claimed design. 

The ornamental design for a ballpoint pen, as shown and described. 